A display panel such as a liquid crystal panel of a display device including a mounting area in a panel surface area thereof has been known. An IC chip that drives the display panel is mounted in the mounting area. Substrates in a pair one of which includes a thin film pattern of semiconductor elements such as thin film transistors (TFTs) are bonded to each other and a bonded substrate is formed. The bonded substrate includes the mounting area in a part thereof and is cleaved with scribing along an outline of the display panel and thus, and a display panel is produced.
A display panel produced with the above producing method generally has a front view of a square outline or a rectangular outline. Recently, according to variety of usage of the display panels, display panels having a non-rectangular outline such as an outline a part of which is curved have been produced. For example, Patent Document 1 discloses a method of producing a liquid crystal panel including a substantially ellipsoidal display area and, that is, a non-rectangular outline shape.